PowerFC wont hold changes????

[zinkrb250]

I took my car 7.5 hours away to get it tuned only to find out my PFC is not working right.

My tuner would enter changes and the PFC will not hold any changes. Once the changes have been made... and the car is shut off... then turned back on... the changes that were made by me or the tuner would be erased and reverted back to the original settings on the PFC....

i.e. injectors 100% duty (original)

67% duty (tuned)

turn car off

turn car back on

100% duty (back to original

I started to think that the PFC isn't getting a constant power source when the car is turned off... but i was just informed that the PFC won't even work if there's no constant wired to it.... which leads me to believe this is a faulty unit.

I ordered this unit from nengun.com and have contacted them requesting the trade me units with a fully functional PFC and pay for overnight shipping...

Any ideas?

cheers -andrew

[BHDave]

This is a common problem in cars that have had engine swaps.

It's to do with the wiring of the eccs relays. Basically when wired correctly the eccs relay maintains power to the ecu for a second or so after the ignition is switched off which is when the pfc saves it's files.

If the car was an auto previously it makes it even more likely as the eccs trigger wire runs through the auto computer, which if unplugged doesn't trip the relay and so the pfc is running constantly off the backup power.

[paulr33]

if you make a change, then go back to setting, and then back to the setting you just changed is it the new value or the old one? i believe the powerfc saves the new value straight away. if you find any setting you make, instantly gets reverted back the tune you have may be password locked out, the powerfc has a function for the tuner to set a "key" on the tune so no settings can be altered. you can't set it or turn it off via the hand controller. only the power excel software or datalogit can set it. a long shot but could be the cause in your case

[paulr33]

either way, when you find out let us know and ill put it into the faq

[zinkrb250]

if you make a change, then go back to setting, and then back to the setting you just changed is it the new value or the old one? i believe the powerfc saves the new value straight away. if you find any setting you make, instantly gets reverted back the tune you have may be password locked out, the powerfc has a function for the tuner to set a "key" on the tune so no settings can be altered. you can't set it or turn it off via the hand controller. only the power excel software or datalogit can set it. a long shot but could be the cause in your case

When I would made a change...then go to settings and back to the new change.... the new change would still be there....But if i made the change and turn the car off... then the new change would revert back to the apexi basemaps.... I was informed by rx7.com that even if you disconnect the battery and leave for several months... the PFC will still have your tuned maps because the information is saved as "volitale data".... so that rules out the theory of a constant power source

[paulr33]

yeah make sense to me,. is the powerfc second hand? if os ask the person you brought it off where they got it tuned. if its brand new then whoever has tuned may have set a tune password

[zinkrb250]

bought the PFC from nengun.com... i believe it's a brand new unit....

I haven't been able to hold a change on this unit since i recieved it. My tuner wasn't using datalogit or excel software so there's no way we could have put a password on it.... nengun.com told me I'll have to send the unit back on my own expense... they'll have it tested at apexi... and if it is in fact a "damaged" unit... then they will replace it... if it's not damaged then I'll be charged for the testing done by apexi

[Thunderbolt]

There was a topic on NS.com similar to what you are experiencing. One person suggested a solution that seemed to work for them:

For me the problem was my alarm. When I turn the ignition off my alarm instantly removes power to my ECU - Power FC doesn't like this - currently I have this imobiliser circuit disabled and I can store. I think the reasoning is as follows: The problem is that the Power FC detects when the ignition is turned off and at that point quickly saves everything to non volatile storage. It probably doesn't dynamically write to the non volatile storage when the unit is running (instead operating only out of ram) because non volatile storage generally has a finite life 10k ->100k writes, which sounds like a lot, but if you do a write every time you update a memory page or similar can quickly be eaten up. Also it can be slow. Anyway upon removing the ignition (turning the engine off with the key) the Power FC requires power for a few more milliseconds to save everything. I think my imobiliser was disabling it before this could occur. I havn't confirmed any timing issues or anything, this sunmisation is based on the fact that disabling the imobiliser fixed it and that people say their Power FC remembers data when not powered.

[zinkrb250]

interesting read.... I wonder if i pull the fuse for my alarm if that will help anything?.... I haven't used the alarm since i bought the car and that was 2 years ago

[williamsf1]

I had the same drama.... I tried the unit in another car.... and same problem... it was the power FC, so I got another FC and it works fine...

sent the problem FC back to the guy I bought it from, and now waiting to hear back!

basically I have been told it is a flash memory problem with the FC and is a comman thing....

if it is new, I would try the unit in another car with an FC same car etc... and if it still does it, its the unit

then send it back to nengun and they will swap it no problems....